1. Field
Embodiments of the invention relate to the field of radio frequency identification (RFID), and more specifically, to radio frequency identification of RFID tags that are located close to an RFID receiver while rejecting RFID tags that are slightly further away.
2. Background
Robotic surgical systems allow surgeons to perform minimally invasive surgery using endoscopic instruments that are controlled by robotic manipulators. Such systems may allow a more intuitive use of the instruments by translating camera views and surgeon hand movements to correspond to what the surgeon would expect in an open surgery.
Typically a robotic surgical system provides a small number of robotic manipulators, perhaps three or four, to which a variety of surgical instruments may be attached. The surgical instruments may be changed during the course of a surgery. The robotic manipulators are typically wrapped with a sterile drape that provides a sterile barrier between the robotic manipulators and the attached surgical instruments.
The robotic surgical system may need to know the identity of the attached instruments so the system can provide the appropriate translation of the camera views and surgeon hand movements. The system may provide information about the identity of the attached instruments to the surgeon to maintain awareness of the current configuration of the system. In some cases, the instruments may be capable of attachment in more than one orientation. The robotic surgical system may need to know the orientation of the attached instruments so the system can provide the appropriate translation of the camera views and surgeon hand movements.
It would be desirable to provide identification of a surgical instrument attached to a surgical robot and separated by a sterile barrier. It would also be desirable to provide the orientation of the surgical instrument.